United States. Bureau of Economic Analysis. "Gross Domestic Product: First Quarter 2012 (Advance Estimate) : Technical Note, BEA 12-17,"
Bureau of Economic Analysis (BEA) News Releases
(April 27, 2012).
https://fraser.stlouisfed.org/title/6148/item/601331/content/pdf/bea_newsreleases_20120427_technical-note, accessed on March 18, 2025.